AliExpress Caught Using Silent Audio for Device Fingerprinting

AliExpress was found using silent audio to fingerprint user devices. Technical author m-c-tech, while debugging Bluetooth earphone failures, discovered that opening the AliExpress homepage cut off phone audio within seconds—muting didn't help, only closing the tab did. By intercepting the AudioContext constructor, they traced it to two background AudioContexts (scripts from collina.js) generating an inaudible fixed waveform for device fingerprinting. This matters because the technique bypasses cookie-based privacy controls and even has a perceptible side effect: Bluetooth audio interruptions.

Confirmed

AliExpress pages run two AudioContexts playing zero-volume, inaudible waveforms with no visible media playback, used for fingerprinting rather than recording
The technique derives a unique audio fingerprint from tiny hardware/browser differences in signal processing, enabling cross-site tracking beyond cookies
It also freezes Bluetooth audio connections and silently collects hardware memory, screen size, and network data
Brave claims its built-in protections can block such cross-site fingerprinting scripts

Why it matters

Audio fingerprinting evades conventional cookie controls and works even when the page is muted, making it hard to detect
For ordinary users, the issue surfaced as mysterious Bluetooth disconnections, showing covert tracking can have real, perceptible side effects

2026-08-23 ~ 2026-08-23 · 5 related posts

Primary sources

AliExpress caught running silent audio fingerprinting that hijacks Bluetooth headphones — xiaohu · 2026-08-23 17:59 (UTC+08:00)
Technical deep dive: How AliExpress WebAudio fingerprinting hijacks Bluetooth audio — xiaohu · 2026-08-23 18:02 (UTC+08:00)
How a Bluetooth hiccup exposed AliExpress's silent WebAudio fingerprinting pipeline — xiaohu · 2026-08-23 18:01 (UTC+08:00)

AliExpress caught using audio beacons for fingerprinting, Brave blocks it — gnukeith · 2026-08-23
AliExpress caught using silent audio waves to fingerprint devices — SumitGup · 2026-08-23
[source] AliExpress caught running silent audio fingerprinting that hijacks Bluetooth headphones — xiaohu · 2026-08-23
[source] How a Bluetooth hiccup exposed AliExpress's silent WebAudio fingerprinting pipeline — xiaohu · 2026-08-23
[source] Technical deep dive: How AliExpress WebAudio fingerprinting hijacks Bluetooth audio — xiaohu · 2026-08-23